Surface Roughness and Cariogenic Microbial Adhesion after Polishing of Smart Chromatic Technology-based Composite Resin

Abstract

This study compared the surface roughness and microbial adhesion characteristics of Omnichroma, a novel composite resin developed using “smart chromatic technology”, with those of two other conventional composite resins with different filler compositions. A total of 144 specimens were fabricated using 3 types of composite resins: Omnichroma (nano-spherical), Filtek Z350XT (nanofill), and Tetric N-Ceram (nanohybrid) and, divided into 3 groups of 48. Finishing was performed using tungsten carbide burs. Specimens were then divided into 3 subgroups using different polishing methods: Control, SofLex, and PoGo. Surface roughness was analyzed quantitatively and qualitatively using an atomic force microscope and a scanning electron microscope. Microbial adhesion was assessed by culturing <i>Streptococcus mutans</i> on the specimens for 24 hours and then measuring colony-forming units attached to the upper surface. The surface roughness (Ra) of Omnichroma was 0.123 μm after finishing, and it exhibited a smooth surface compared to the other resins. However, after polishing, there were no significant differences in the surface roughness between the three composite groups, regardless of the polishing methods. The surfaces of the Control subgroups were significantly rougher than those of the SofLex subgroups in all 3 composite groups. However, except for Tetric N-Ceram, there were no significant differences between the Control and PoGo subgroups in the other composite groups. Microbial adhesion assessment showed no significant differences between any of the 3 composite resin subgroups; however, Omnichroma exhibited higher microbial adhesion than the other two composites. No significant correlation was observed between surface roughness and microbial adhesion.

One step polishing to compare the mean surface roughness of nanohybrid and microhybrid composite resins

“…These findings are in line with studies conducted by Naser-Alavi et al 11 and Amaya-Pajares et al 12 , which demonstrated that nano hybrid composites show better polish ability than micro hybrid composites. However, it was found in another study by Kim et al 13 that nano hybrid composite had lower smoothness and polish ability to micro hybrid composite. Because nano hybrid composite has a lower surface roughness and better polish ability than micro hybrid composite, this study's findings are encouraging and consistent with many earlier investigations.…”